岩土工程学报2024，Vol.46Issue(z2)：11-15,5.DOI:10.11779/CJGE2024S20006
干湿循环对黏土微观结构及持水性能影响的试验研究
Experimental study on influences of wetting-drying cycles on microstructure and water-retention characteristics of clay
摘要
Abstract
The Long-term wetting-drying cycles can weaken the engineering characteristics of subgrade fillers,resulting in engineering disasters.It is necessary to study the effects of the wetting-drying cycles on their microstructure and water-retention performance.A series of mercury intrusion tests,scanning electron microscopy tests,pressure plate tests and saturated salt solution vapor equilibrium tests considering the influences of the wetting-drying cycles are carried out on the subgrade filler of the existing ballasted track roads.The experimental results show that during repeated wetting-drying cycles,the soil structure is damaged,and the internal cementitious materials are continuously reduced.The number of micropores and small pores(<5 μm)in the soil gradually increases,while the peak pore size in the range of mesopores and some large pores(5～30 μm)gradually decreases,and the distribution density gradually increases.After several wetting-drying cycles,the number of microcracks(>100 μm)gradually increases,leading to cracking of the soil specimens.The wetting-drying cycles have effects on the water-retention characteristics of the soil.When the initial dry density is low,the air-entry value after experiencing one wetting-drying cycle is slightly higher than that without wetting-drying cycles,while the air-entry value of the specimen after three and five wetting-drying cycles continues to decrease.关键词
干湿循环/有砟铁路黏土填料/微观结构/持水性能Key words
wetting-drying cycle/ballasted railway clay filler/microstructure/water-retention characteristic分类
建筑与水利引用本文复制引用
杨旭,蔡国庆,刘倩倩,李风增,单冶鹏..干湿循环对黏土微观结构及持水性能影响的试验研究[J].岩土工程学报,2024,46(z2):11-15,5.基金项目
国家自然科学基金项目(U2034204,52078031),中央高校基本科研业务费项目(2023JBZD004) （U2034204,52078031）
